# 2.1. Array Create¶

## 2.1.1. SetUp¶

>>> import numpy as np


## 2.1.2. Declare¶

1-dimensional Array:

>>> np.array([1, 2, 3])
array([1, 2, 3])
>>>
>>> np.array([1.0, 2.0, 3.0])
array([1., 2., 3.])
>>>
>>> np.array([1.1, 2.2, 3.3])
array([1.1, 2.2, 3.3])
>>>
>>> np.array([1, 2, 3], float)
array([1., 2., 3.])
>>>
>>> np.array([1, 2, 3], dtype=float)
array([1., 2., 3.])


2-dimensional Array:

>>> np.array([[1, 2, 3],
...           [4, 5, 6],
...           [7, 8, 9]])
array([[1, 2, 3],
[4, 5, 6],
[7, 8, 9]])


3-dimensional Array:

>>> np.array([[[1, 2, 3],
...            [4, 5, 6],
...            [7, 8, 9]],
...
...           [[1, 2, 3],
...            [4, 5, 6],
...            [7, 8, 9]]])
...
array([[[1, 2, 3],
[4, 5, 6],
[7, 8, 9]],

[[1, 2, 3],
[4, 5, 6],
[7, 8, 9]]])


## 2.1.3. Stringify¶

>>> a = np.array([[1, 2, 3],
...               [4, 5, 6],
...               [7, 8, 9]])
>>>
>>> str(a)
'[[1 2 3]\n [4 5 6]\n [7 8 9]]'
>>>
>>> print(a)
[[1 2 3]
[4 5 6]
[7 8 9]]
>>>
>>> repr(a)
'array([[1, 2, 3],\n       [4, 5, 6],\n       [7, 8, 9]])'
>>>
>>> a
array([[1, 2, 3],
[4, 5, 6],
[7, 8, 9]])
>>>
>>> print(repr(a))
array([[1, 2, 3],
[4, 5, 6],
[7, 8, 9]])


## 2.1.4. Recap¶

>>> a = np.array([1, 2, 3])
>>> b = np.array(range(0, 10))


## 2.1.5. References¶

1

https://i.ytimg.com/vi/iCOhz07Ng6g/maxresdefault.jpg

## 2.1.6. Assignments¶

"""
* Assignment: Numpy Create Arange
* Complexity: easy
* Lines of code: 1 lines
* Time: 3 min

English:
1. Create result: np.ndarray with even numbers from 0 to 100 (without 100)
2. Numbers must be float type
3. Run doctests - all must succeed

Polish:
1. Stwórz result: np.ndarray z liczbami parzystymi od 0 do 100 (bez 100)
2. Liczby muszą być typu float
3. Uruchom doctesty - wszystkie muszą się powieść

Tests:
>>> import sys; sys.tracebacklimit = 0

>>> assert result is not Ellipsis, \
'Assign result to variable: result'
>>> assert type(result) is np.ndarray, \
'Variable result has invalid type, expected: np.ndarray'

>>> result
array([ 0.,  2.,  4.,  6.,  8., 10., 12., 14., 16., 18., 20., 22., 24.,
26., 28., 30., 32., 34., 36., 38., 40., 42., 44., 46., 48., 50.,
52., 54., 56., 58., 60., 62., 64., 66., 68., 70., 72., 74., 76.,
78., 80., 82., 84., 86., 88., 90., 92., 94., 96., 98.])
"""

import numpy as np

result = ...